Shamsiel

Exactly. Now imagine if instead of a 1.06 it was a .82 twinscroll or smaller. For the kind of power shown here it wouldn't fall off up top just yet, and it would spool 1000-1500 rpm sooner.

morrisman1

New to the forum, joined to contibute to this thread.

Ive not long got my 4g63 Mirage set up and it runs the s200sx-e 7670, on a 1.15AR T4 twin scroll exhaust housing. This housing has T3 sized ports, so for all practical purposes is a twin scroll T3.

Attached is a dyno sheet, but some basic background work. It's a 6 bolt 2.3L engine with the Evo small port head. Kelford TX278 cams. I build the manifold but its very similar to the Mr Peepers T3 twin scroll one from morrison fabrications. Exhaust is just a straight pipe 3". On the dyno IATs were pretty high due to lack of air flow, but on the track they are fine. Intake is an Evo4, 70mm throttle body. Fuel is E50

On track response is pretty good, have a look at this video for some practical data. It spools super quick on gear changes, and boost threshold is nice and low. It does feel like at 25psi I am starting to run out of compressor based on how the engine responds to more boost. This run was done on base boost of 16psi with a little bit of increase boost up top. Bit of a waste of time as hardly touched the extra boost zones and it didnt give the extra bulk torque that the extra boost gives in the midrange, but it did at least help hold the gearbox together!

Packaging I have noticed that the turbine housing is quite large compared to some turbos, but I built the manifold to suit so who cares.

Shamsiel

^^ Wowwwww would you look at that? It's almost like when I said if you pair this turbo with a twinscroll turbine housing it would spool another 1500rpm faster...... Not only that but his AR size is muchhh larger than my .82 and still spools faster.....It's like I knew what the hell I was talking about, crazy huh?

Anyway here's some footage of me roll racing with my setup. You'll see this turbo has amazing top end power for what it is. Excuse my bad driving though, my trans is on the way out and I have to granny shift. That being said even with this setup my car is a easily a low 11 to high 10 second car.

Shamsiel

I could have sworn you uploaded some dynapack graphs earlier... Did you remove them or am just crazy?

morrisman1

They are still there!

The advantages of the twin scroll I believe go beyond boost threshold and spool time, the response at part throttle, when feathering throttle in turns etc is brilliant, its very much like driving an N/A except with a bit more grunt. I don't run a blow off valve, that doesn't appear to have any negative effects at all (and I'm happy with the 360 degree thrust and large centre shaft the Borg will not be damaged)

Obviously given the type of racing that I am doing, there is a significant amount more importance on having a huge and usable mid range power,and this turbo seems to fit that requirement well. Looking forwards to getting the new gearbox together so I can throw a bit more boost at it.

Shamsiel

For some reason they're not showing up for me on the site but I can see them in my email notifications. Anyway, I would say that you not running a BOV is largely why you have such good throttle responce, sounds pretty sketchy imo but, hey its seems like less of a risk than antilag. I would have just ran a 100% recirculating bov still using MAF tuning and called it a day.

2winscroll

Hahahaaa, look at the data Morrisman has posted!
Eat some crow RWD4G63!
twin scroll, T3 housing will spool crazy fast with good top end.
You would NEVER get a T4 twin scroll to spool even close to this fast.
looks like your the one with a rough grasp bro!

RWD4G63

Lol, it’s a T4 divided flange dumbass. You still don’t understand that Area/Radius is what matters and that T4 divided will and does spool just as fast as T3 divided if the right A/R is chosen. It’s not the flange, it’s the A/R. T4 divided is usually available in better sizes and is easier to work on and has more durable gaskets.

RS200

iTrader: (1)

I think this was mentioned already, but the S200SX "T4" is just the T4 footprint with T3-sized ports.



I've seen some T4 housings outspool T3 for the same A/R and make bigger numbers peak. There's a reason why the EFR line twin scrolls are T4-only, and single scrolls T3 only (for the bigger ones, anyway). Either way, twin scroll has a major effect on how big turbo cars respond.

RWD4G63

Yeah, that’s why 2winscroll thinks he “got me”. He just doesn’t understand how turbine housings work. The username is the most ironic one on this forum.

2winscroll

Better watch who you call a dumbass ****....

I totally understand how a/r , gas velocitys and how they work. A T4 header has larger pipes and bigger merge collector, this reduces velocity’s inside the header causing more lag. Like I said before a dramatic improvement in transient response can be had from a short and small tube header.

I build my own headers, everything from motorcycles, snowmobiles, and cars. I have more knowledge in my big toe than you will ever have. Got that way from listening to others and having an open mind, something you should learn how to do.

2winscroll

Put a production made T4 twin scroll on morrisman’s setup and I will guarantee it will lose a few hundred rpm of scroll, it’s not even debatable.

A mass produced T4 twin scroll manifold usually can support around 1000hp, it’s not a good choice for a quick spooling manifold with this turbo is what I was trying to say at the beginning of this thread. Then you had to interject and tell me I have a rough grasp on turbine housings. You are wrong on both counts.

I especially like your statement that a turbo spools due too 30 percent velocity and 70 percent heat. Heat causes expansion which in turn causes more velocity of gases.
take a compressed air gun and blow it through your turbine housing, then take a blow torch and do the same, which one makes the turbine spin you fool!

RWD4G63

HAHAHAHA. When did you ever say anything about “production manifolds”? Your statement was and always has been a general “T3 divided spools faster than T4 divided” which is patently false. Don’t start backpedaling now, it just makes you look like more of a fool.
There are several small-runner T4 manifolds on the market, and yes, they do help spool over larger-runner versions. Everybody knows this. Morrismans manifold is clearly large runner.

2winscroll

Not backpedaling at all, I’ll say it again, the T3 ports are perfect size for spoiling these turbos quickly. Your the fool that says it doesn’t matter (now you can go edit it))

2winscroll

Your not worth arguing with you, your a know it all